class Solution:
    def numDistinct(self, s: str, t: str) -> int:
        length1 = len(s)
        length2 = len(t)
        dp = [[0 for _ in range(length1 + 1)] for _ in range(length2 + 1)]
        for j in range(length1 + 1):
            dp[0][j] = 1
        for i in range(1, length2 + 1):
            for j in range(1, length1 + 1):
                if t[i - 1] == s[j - 1]:
                    dp[i][j] = dp[i - 1][j - 1] + dp[i][j - 1]
                else:
                    dp[i][j] = dp[i][j - 1]
        return dp[-1][-1]


if __name__ == '__main__':
    s = Solution()
    r = s.numDistinct("baag", t="bag")
    print(r)
